The present invention relates to an umbrella with vents on the umbrella cloth for venting wind, wherein by changing the shape of the umbrella cloth and adding a portion formed by a plurality of suspending cambered-elements, the wind within the umbrella can vent out rapidly and thus the wind pressure within the umbrella is released.
The umbrella is a tool for shielding sunlight or raindrops. In general, an umbrella mainly comprises an umbrella frame and umbrella cloths for shielding sunlight and rain. The umbrella frame has a shaft and a plurality of main ribs and a plurality of supporting ribs. The umbrella cloth covers the umbrella frame so that as the umbrella is expanded, it can be used to shield raindrops or sunlight. After the umbrella is folded, it can be carried and stored conveniently.
As described hereinabove, the umbrella cloth is formed by a single layer of opaque cloth. In general, the structure of the umbrella cloth is dense for achieving the object of shielding sunlight and rain. Therefore, it is not preferred in air ventilation. Therefore, as the user walks with holding an umbrella in sunlight or rains, since air under the umbrella cloth can not be ventilated effectively, and further since a high temperature will be induced from the radiation of sunlight so that the space in the umbrella will be dull and thus, the user will feel uneasy. Furthermore, in typhoon, the wind pressure within the umbrella can not be released effectively and thus it is often the umbrella will turn upside down.
In order to increment the effect of ventilation, the prior art umbrella provides to structures. One is illustrated in FIG. 9, wherein the umbrella cloth 3 is formed by a lower cloth 30 and an upper cloth 31. In order to match the expansion of the main ribs 41, a plurality of openings 301 are formed between the lower cloth 30 and the main ribs 41. The upper cloth 31 is slightly smaller than the lower cloth. When the umbrella is assembled, the upper cloth 31 covers concentrically on the lower cloth 30 and then they are firmly secured to each main rib 41 of the umbrella frame 40. The plurality of openings 301 of the lower cloth 30 is shielded by the upper cloth 31. By this compound type umbrella cloth, when the umbrella is expanded, air may flow into gaps between the periphery 311 of the upper cloth 31 and the lower cloth 30. Then, the air flows to the space of the umbrella from the openings 301 in the upper cloth 30 so as to increase the flowing of the air under the umbrella or to prevent the umbrella from turning upside down as a large wind applies thereon.
Another structure of the umbrella is illustrated in FIG. 10, in that the umbrella 5 has a lower cloth 50 and an upper cloth 51. The lower cloth 50 is formed to be matched to the configuration of a complete expanding main ribs. The center of the lower cloth 50 is installed with a round web 501. As the umbrella is expanded for use, air flows into the gap between the periphery 511 of the upper cloth 51 and the web cloth 501 of the lower cloth 50 so as to increase the air convection in the umbrella, or the air may flow in the reverse direction so as to release the air pressure in the umbrella.
However, there are many defects in the aforesaid two compound umbrella cloth structure so that the use and manufacturing of the umbrella can not achieve an optimum effect. The reasons will be described in the following:
1. The effects of air convection and venting of wind pressure are not good: in the aforesaid two structures, the upper and lower umbrella cloths are concentrically overlapped on the umbrella ribs. When the umbrella is expanded, the upper and lower umbrella cloths are expanded by the main ribs. The outer periphery of the upper cloth almost adhered to the surface of the lower cloth so that the gap between the upper cloth and the lower cloth is too small, and thus air can not flow into the space in the umbrella successfully, or the wind pressure in the umbrella can not be smoothly released out. As a result, the effects of air convection and venting of wind pressure is not preferred.
2. Too much material is necessary for the umbrella cloths: in the aforesaid to prior art compound umbrella cloth, the upper cloth and lower cloth have a larger area so that overlapping area between the upper cloth and lower cloth are too large to be suitable. Especially, the outer periphery of the upper cloth shown in FIG. 9 is expanded by expensive elastic strips and then is fixed to the periphery of the lower cloth so that the cost for the material of the umbrella cloth is high.
3. The process for manufacturing the umbrella is complex: in the aforesaid prior art compound type structure, other than using umbrella cloth with a larger area, the lower cloth is formed with a plurality of openings or is connected to web cloth for air convection or venting of wind pressure. Therefore, the process for manufacturing the lower cloth is complex.
With reference to FIGS. 11 and 12, the U.S. Pat. No. 6,155,278 discloses a further prior art umbrella. The umbrellas can be used to improve the defects in the aforesaid two prior art umbrellas. In this prior art, the inner periphery of the lower cloth 21 has two sides which are formed with extension portions 212 on the main ribs 11. After it is stitched with the main ribs, a triangular overlapping portion 214 is formed, which is formed with a wind outlet 202 between the lower edge 201 of the upper cloth 20 and the upper edge 211 of the lower cloth 21 (see FIG. 12). Since the wind outlet 202 is confined to the tension force at two end points as the extension portion 212 is firmly stitched to the main ribs 11. Therefore, a large wind outlet 202 can not be achieved. Furthermore, an angle of almost 90 degrees is formed between the extension portion 212 and the upper edge 211 of each unit cloth of the lower cloth 21, it is very difficult in stitching the umbrella cloth. The stitching speed will be reduced greatly so that the manufacturing cost is high. Moreover, each unit cloth in the lower edge 201 of the upper cloth 20 is stitched to its respective unit cloth of the lower cloth 21 in a tension condition. Therefore, the wind outlet 202 is narrow and thus, the effect of venting wind pressure is very slight.
Accordingly, the primary object of the present invention is to provide an umbrella with vents on the umbrella cloth for venting wind pressure and increasing the convection of air under the umbrella cloth so that the manufacturing process is simplified and the cost is down.
To achieve above objects, the present invention provides an umbrella with vents on the umbrella cloth for venting wind. The umbrella comprises an umbrella frame and an umbrella cloth. The umbrella cloth comprises an upper cloth and a lower cloth. The upper cloth occupies most space of a surface of the umbrella; and the lower cloth is installed at a lower periphery. A lower periphery of the upper cloth covers upon the upper periphery of the lower cloth. An upper periphery of each unit of the lower cloth is a non-linear cambered portion. A suspending element is combined to the cambered upper portion of the lower cloth so as to be formed as a continuous multiple-lobe element having a plurality of cambered-recess portions at the upper periphery of the lower cloth. Therefore, an upper periphery of each unit of the lower cloth is loosely connected to each respective unit of upper cloth so that a plurality of vents are formed between the upper periphery of the lower cloth and the lower periphery of the upper cloth. As a result, the convection of air under the umbrella cloth is increased and the wind pressure is released.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing.